1. Field
This following description relates to an electrolyte for a rechargeable lithium battery and a rechargeable lithium battery including the same.
2. Description of the Related Art
Rechargeable lithium batteries have recently drawn attention as a power source for small portable electronic devices. The rechargeable lithium batteries use an organic electrolyte and thereby, have discharge voltages that are two or more times higher than that of conventional batteries using an alkali aqueous solution and accordingly, have high energy density.
The rechargeable lithium batteries are used by injecting an electrolyte into a battery cell including a positive electrode including a positive active material (that may intercalate and deintercalate lithium) and a negative electrode including a negative active material (that may intercalate and deintercalate lithium).
The electrolyte may be prepared by dissolving a lithium salt in an organic solvent but limit battery performance when a lithium ion battery is allowed to stand at a high temperature.
Comparatively, a comparative electrolyte for a rechargeable lithium battery has included a cyclic ester such as ethylene carbonate, propylene carbonate, or the like, a linear ester such as dimethyl carbonate, propionic acid ether, or the like, a cyclic ether such as tetrahydrofuran or the like. However, the comparable electrolyte did not satisfy both safety and long-term charge-discharge cycle-life characteristics.
In order to accomplish the long-term charge-discharge cycle-life characteristics of a rechargeable lithium battery, an electrolyte including an organic fluoro ether compound having excellent safety against oxidation decomposition has been recently suggested.
The organic fluoro ether compound includes fluoro in a high amount and thus, high safety against oxidation decomposition but this deteriorates the cycle-life characteristics (capacity retention) due to high viscosity of the utilized fluoro-based solvent.